Filter by-pass valve construction



A ril 20, 1948.

W. KASTEN FILTER BY-PASS VALVE CONSTRUCTION Filed Aug. 23, 1944 PatentedApr. 20, 1948 FILTER BY -PA SS VALVE CONSTRUCTION -Walter Kasten,Franklin, Mich, anl nor, by

mesne assignments,

to Bendix Aviation Corporation (Delaware), Detroit, Mich., a corporationof Delaware Application August 23, 1944, Serial No. 550,842

' ICIaim. (Cl.2l183) The present invention concerns certain features ofbetterment in filters and it relates more particularly to novelstructural and functional ad-' vantages in a valve-mechanism controllinga bypass around the filter-element which is automatically opened whenand if such element becomes more or less clogged, so that the fluid fiowthrough the filter housing or casing will not be stopped although thefiltering function is thus tempo-.

.rarily suspended.

Structures of this general character or type have been heretofore knownand used, but this invention possesses certain innovatory features ofsubstantial value in the construction of the filter and in theefiiciency of its operation.

In order that those skilled in this art may fully understand theinvention, its incorporation in appropriate physical form has beenillustrated in detail in the accompanying drawing, which forms a part ofthis specification, and to which reference should be had in connectionwith the fol-' lowing description. I

For simplicity, like reference numerals have been employed in thedrawing to designate the same structural members in the different views.

The invention, of course, maybe embodied satisfactorily in various typesand styles of filters; for convenience. however, it is presented hereinin a filter of the general form set forth in U. S. Patent No. 2,360,020,Skinner and Kasten, granted October 10, 1944.

In this drawing- I Figure 1 is a general perspective view of thecomplete filter;

Figure 2 is a longitudinal or vertical section on a larger scale on line2-2 of Figure 1 with its lower portion slightly in perspective; and

Figure 3 is a horizontal section on line 3-3 of Figure 2.

Referring to the drawing, it will be observed that the new and improvedfilter includes a main,

hollow, supporting body, casting or head II provided with ascrew-threaded inlet-passage l2 communicating with the side of the main,cylindrical chamber Hi, the latter having downwardly-open, larger,internally-screw-threaded mouth It, chamber l3 also having areduceddiameter, cylindrical, centrally-located, upward extension [5connected to a screw-threaded outlet or discharge passage [6, thecasting Ii being and a ring-shaped conical valve 32,

fitted with a pair of apertured, 0ppositely=-0ut standing lugs or earsll, II by meansof which and bolts or screws (not shown) the filter maybe fastened to a suitable support. I 5 The filter-element, whichperforms the filtering operation, includes a central, internal,longitudinally-bent, sheet-metal rod it having three more or lessradiallydisposed ribs or arms, of which one It is of double-thickness ofmetal, whereas the other two 20, 2! are of single thickness withlaterally-bent sections 22, '22, the lower end of v such rod havingthree downwardly-directed ears 23, 23, 23 extended through holes in anend metal disc or terminal member 25 and bent over below the disc tohold the latter fixedly attached p'ermanently to the rod, such disc 25having in addition marginal ears 21, 21!, 21 bent down around the topring or convolution of a spiral-spring 28 thus fixedly securing thespring to the under side of the disc.

The present filter includes an edge-filtration stack or pack 30 ofwasher-shaped, uneven-surface paper or other comparable discs, or afilterelement composed of the helically-wound convolutions of a ribbonof the same material, suitably charged or impregnated with an agent,which prevents the liquid or gas to be filtered or any of itscontaminants or diluents from deleteriously or injuriously affecting thematerial of the bodies of the discs or'windings, said discs orconvolutions being mounted face-to-face on, and maintained in superposedregister with one another by the rod IS. The diameter of the discs orconvolutions is practically the same as the internal caliber of ment 30.the bottom disc or layer bearing on the uppersurface of a neoprene orother similar disc 2i! on the top surface of the end member 25 whichcloses the lower end of the passage mentioned.

The top disc or convolution of the element 30 bears against the undersurface of a neoprene layer 3| interposed between such top of the filtereach of the two elements 29 and 3| being desirably adhered at itsopposite sides to the'members with which it is-in'contact.

Valve-member 32 cooperates with a conical seat 33on the lower face of ametal, ring-shaped, valve-seat member 34 snugly fitting inside of the nocylindrical wall 35 of a sheet-metal, round, comthe central passage ofthe stationary filter-ele-' upwardly roviding a round central opening,and

then outwardly, these three parts clamping firmly and fixedly betweenthem the round inner portion of a ring-shaped leather or othercomparable gasket 36 of right-angle cross-section.

The outer circular section of such gasket is located between the topportion of the round wall of chamber i3 and the circular outer surfaceof member 35,- the lower edge of such gasket being bevelled upwardlyinwardly as shown.

A sheet-metal shell or casing 39 with a rounded, lower end 4! and anoutstanding, circular flange d2 surrounding the top, open mouth of themember 39 encloses a substantial portion of the filter-pack 30 and apart ofthe barrier 35, the top face of such casing-flange 42 bearingagainst the under surface of a. ring-gasket d8 of suitable material,dependent upon the nature of the material to he filtered, for instance aneoprene' gasket if oil is to be filtered. The upper face of gasket 43presses against a, fiat, horizontal shoulder ll of the main-body ll,another ring-gasket 45 being interposed between the under surface 01'the flange 42 and the top flat end of a hollow nut 48 having an angularhead 4'! by which it may be turned, the exterior screwthread of the nutcoasting with the internal screw-thread ll of casting ll, whereby thenut in its normal position .forces the three parts 43,

' 42 and 45 into pressure-tight relation with one another and with thenut and the main-body.

' When the parts are in their assembled positions indicated in Figure 2,the casing 39 compresses spring 28 and the latter pushes the filterpacl:assembly up sufllciently to hold the gasket 36 in firm engagement withthe upper end-wall of chamber i3.

A coiled spring 31 of suitable strength is interposed between the topsurface of the ring-shaped, centrally-apertured valve-seat member 34 andthe under surface of the centrally-open end-wall of the barrier 35, across-pin 38 extended through registered apertures in the upper portionof rod l8 bearing on the top surface of such barrier. end-wall andthereby maintaining such spring under a predetermined compression whichforce is obviously transmitted to element normally holding the valveclosed and the parts of the filter-element pressed, together.

Ordinarily also opposed to the pressure or the spring on thevalve-member 34 is the upward pressure of the unfiltered fluid, liquidor-gas, inside; of the barrier 85 on the under annular surface of thepart 34 outwardly beyond its conical valve-seat 33, but when the filteris filtering properly, such upward pressure sufiicient to overcome thedownward pressure of the spring and the valve remains closed.

It should also be borne in mind that whenfithe filter is functioningefiiciently, the pressure of the filtered fluid also acts downwardly onthe top surface of the element 3, but the upward pres-' sure of theunfiltered fluid is inadequate to overcome both downward pressures onsuch part.

Cross-pin 38 occupying cavity or chamber i5 is longer than the diameterpassage l6 and when rod 18 rises by reason of increased pressure on theunderside of end-clocrease of valve and sure 25, due to clogging of thefilter pack, such ascent is terminated when the end portions of the pinengage the top surface of chamber l5, thus limiting the compression ofspring 81 and its eflect on valve-member 34, whereas further inpressureon the underside of member 34 causes the continued discharge of thefluid although it is not properly filtered.

When the pressure drop oi the filtered fluid decreases substantially byreason of partial or total clogging oi the filter. then the specifiedupward pressure of the unfiltered fluid on the valvemember 34 issufflcient to force such member upwardly and to open the valve, so thatthe fiuid thereafter passes directly from the inlet to the the filter iscleaned or replaced with a new one,

Stated somewhat differently, it should be-observed that, when thisincrease in pressure of the unfiltered fluid occurs and such augmentedpressure acts upwardly on the filter-pack disc 25, it forces thefilter-unit and supplemental valveconstruction up until the cross-pin 38engages the top surface of chamber I5, whereupon no further upwardtravel of the filter-pack can take place, but such increasedfluid-pressure acting on the underside of ring 34 lifts the latter,against the action or spring 31 and the lesser fluid-pressure above suchelement 34, stationary conical-valve member 32 opening the by-passbetween the parts unfiltered fiuid to flow therethrough short-cirouitingthe filter-element.

It might be noted in passing that during normal operation of the filter,the pressure of the illtered fiuid acts downwardly on the disc 25 at thelower end of the filter-element, but this is of no moment because thevalve 32 cannot respond to housing operative between such pressure dueto the constant upholding action of the cross-pin 38. Also, whenvalve-seat member 34 opens as indicated a somewhat greater pressure maybe exerted on disc 25 but the valvemember32 does not descend.

From what the circular barrier it performs the novel muluting the fluidto be filtered, of supplying a hous-.

structure set forth herein since reasonable modi- In a filter of knowntype having a housing with an inlet and outlet, a hollow filter-elementin said said inlet and outlet and with its interior connected to saidoutlet, and

of the dischargea hollow barrier enclosing at least a part of the lengthof said filter-element and spaced therefrom and having an aperturedend-wall through which the filter-element discharges its filtered fiuidinto said outlet, the novel improvement of a normally-closed bypass forsaid filter-element including a spring-closed valve having a valveseatmember and a valve-member both of which are outside of, and apertured inregister with,

the opening 01' the short-'circuitlng away from the now I2 and 84allowing the asaao'ao said filter-element, one of said members beinsmounted on the discharge end 01 said filter-ele-,

ment and communicating with its interior, the other cooperating memberbeing inside of, slidable in, and guided by, said barrier and subjectedto the pressure of the unfiltered fluid in said houaing, the spring ofsaid valve being located in said barrier and acting on said cooperatingmember to maintain the valve normally closed.

" WALTER KASTEN.

REFERENCES CITED The following references are of record in the file ofthis patent:

mm s'rafms PATENTS Number Number

